The invention relates to a brake system of the type described herein and finally claimed. A brake system of this kind is known (ATZ--Automobiltechnische Zeitschrift 79 (1977), Number 11, pages 499 and 500).
A known brake system of this kind has a pump which feeds fluid into a pressure line in which a flow governor is located. Via the flow governor, in case of necessity, a pressure reservoir is filled by throttling the circulation. When the brake pedal is actuated, the energy stored in the reservoir is utilized.
Generally, the brake system is combined with a hydraulic auxiliary-force steering mechanism in the steering gear of which the supply flow of the pump is throttled in case of necessity, in order thus to create a form of boost in the steering function. From the consumers, the fluid then flows back into the reservoir.
If the reservoir is not filled, the fluid supply flow of the pump flows unrestricted from the flow governor of the brake system to the steering mechanism. When the reservoir is being filled, only about 10% of the supply flow of the pump is diverted from the steering to the brake system. The brake thus requires only a small amount of pressure fluid, while the steering operation is a heavy consumer. The pump must therefore be very large, and care must be taken to provide a separate means of carrying off heat therefrom.
In addition, the flow governor in the known system has a switching period; when this is not met, the reservoir is filled, and when it is exceeded, the reservoir filling is set. However, as a result, the reservoir diaphragm, given a relatively high pressure level, is continuously exposed to pressure fluctuations which have an adverse effect on the length of its life.